# Copyright 2013 Rackspace Hosting
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

from novaclient import api_versions
from novaclient import base
from novaclient.i18n import _
from novaclient import utils


class EvacuateHostResponse(base.Resource):
    pass


def _server_evacuate(cs, server, args):
    success = True
    error_message = ""
    try:
        if api_versions.APIVersion("2.29") <= cs.api_version:
            # if microversion >= 2.29
            force = getattr(args, 'force', None)
            cs.servers.evacuate(server=server['uuid'], host=args.target_host,
                                force=force)
        elif api_versions.APIVersion("2.14") <= cs.api_version:
            # if microversion 2.14 - 2.28
            cs.servers.evacuate(server=server['uuid'], host=args.target_host)
        else:
            # else microversion 2.0 - 2.13
            on_shared_storage = getattr(args, 'on_shared_storage', None)
            cs.servers.evacuate(server=server['uuid'],
                                host=args.target_host,
                                on_shared_storage=on_shared_storage)
    except Exception as e:
        success = False
        error_message = _("Error while evacuating instance: %s") % e
    return EvacuateHostResponse(base.Manager,
                                {"server_uuid": server['uuid'],
                                 "evacuate_accepted": success,
                                 "error_message": error_message})


@utils.arg('host', metavar='<host>', help='Name of host.')
@utils.arg(
    '--target_host',
    metavar='<target_host>',
    default=None,
    help=_('Name of target host. If no host is specified the scheduler will '
           'select a target.'))
@utils.arg(
    '--on-shared-storage',
    dest='on_shared_storage',
    action="store_true",
    default=False,
    help=_('Specifies whether all instances files are on shared storage'),
    start_version='2.0',
    end_version='2.13')
@utils.arg(
    '--force',
    dest='force',
    action='store_true',
    default=False,
    help=_('Force to not verify the scheduler if a host is provided.'),
    start_version='2.29')
def do_host_evacuate(cs, args):
    """Evacuate all instances from failed host."""
    hypervisors = cs.hypervisors.search(args.host, servers=True)
    response = []
    for hyper in hypervisors:
        if hasattr(hyper, 'servers'):
            for server in hyper.servers:
                response.append(_server_evacuate(cs, server, args))

    utils.print_list(response,
                     ["Server UUID", "Evacuate Accepted", "Error Message"])
